The rookie right-hander doesn't think that'll be an issue moving forward.Wheeler will make his Citi Field debut Sunday in the series finale against the Washington Nationals.While it's hard to make many conclusions about Wheeler (1-0, 3.18 ERA) after two major league starts, Collins -- and others -- noticed the 23-year-old has been telegraphing his off-speed stuff. Collins said the staff briefly addressed it with Wheeler during a 5-4 loss to the Chicago White Sox on Tuesday when he gave up four runs in 5 1/3 innings."Guys look for it all the time. It starts with the glove," said Collins, who said he received about 10 text messages and emails from those who pinpointed Wheeler's flaw. "Moving the glove there's different things to look for and then all of sudden you start to look when he speeds up, when he slows down, what the pitches are. You start to get a read on it."Wheeler, who threw six shutout innings in his debut -- a 6-1 victory over Atlanta on June 18 -- also has been working with pitching coach Dan Warthen to correct his arm slot."I don't think it's anything too difficult," the 2009 first-round pick told the Mets' official website. "Just a little small tweak here and there, and we'll be good to go."Wheeler's curveball improved his last time out, but getting ahead of hitters -- he's already thrown 211 pitches and walked eight -- are a concern.So is the Mets' 15-24 record in Queens, but New York (33-44) has a chance to win its second series over the Nationals (40-40) in town this season after evening this three-game set with Saturday's 5-1 victory.Winners of nine of 14 overall, the Mets will get their second look at Gio Gonzalez (4-3, 3.31) this season.The left-hander yielded five runs, walked four and lasted just four innings in a 7-6 victory at Citi Field on April 20 -- the Nationals' only victory in that three-game set.Since then, Gonzalez has surrendered two runs or fewer in 10 of 12 starts. He has a 2.16 ERA in five appearances this month, but he has just one win to show for that. That came Tuesday when he allowed two runs in 6 1/3 innings of a 7-5 win over Arizona, his first victory in nine starts.The two-time All-Star had a 2.18 run-support average since his last victory May 5."Seeing these guys come alive, swing the bat, it's always a nice thing to see, especially when you start getting in a rhythm like that," Gonzalez said.Mets newcomer Eric Young Jr. is in a nice rhythm, batting .400 with seven RBIs during a team-best eight-game hitting streak.New York's Marlon Byrd and David Wright, who both went 1 for 2 off Gonzalez on April 20, lead the team with six and five homers, respectively, this month.Washington shortstop Ian Desmond has eight homers this month with 25 RBIs -- the most by a National in June. The franchise record for RBIs in June was 30 set by Moises Alou in 1994 with Montreal.Desmond has team highs of three homers and five RBIs as Washington has dropped four of seven to New York this season.